Metal injection molding provides a technique for forming net-shape and near net-shape metal articles. Alternative techniques for forming metal articles include molten metal casting, solid metal machining, and metal powder pressing. Typically, the alternative techniques require extended processing to impart fine details or to form complex shapes. Further, deburring and polishing are often required with the alternative methods.
Metal injection molding feedstocks typically include components to assist a molded article retain its shape and withstand the processing required to form the final metal article. Often times, metal injection molding feedstocks include binders. Wax, polymer, and aqueous binders have been used. Lubricants, sintering aids, such as silver, and other additives are employed in known feedstock mixtures. A variety of metals and metal alloys, including copper, stainless steel, titanium, tantalum, and cobalt have been used for different applications.
Metal articles formed via metal injection molding can be used in a variety of industries including the medical, aerospace, and consumer goods industries. Metal articles can be used for surgical implements and surgical implants, among other uses. Certain industries, such as the medical and aerospace industries, have stringent requirements for the properties of metal articles. For example, enhanced ductility, density, and purity are often required to meet product specifications and standards, such as applicable American Society for Testing and Materials (ASTM) International standards.
Examples of metal injection molding methods and feedstocks and other metal processing techniques are disclosed in the following US patent and patent application references, which are hereby incorporated by reference for all purposes: U.S. Pat. Nos. 5,159,007; 5,211,775; 5,308,576; 5,848,350; 6,725,901; 2005/0196312; 2006/0285991; 2007/0065329; and 2007/0068340.
Further examples of metal injection molding methods and feedstocks are disclosed in the following non-patent references, which are hereby incorporated by reference:
“A New Binder for Powder Injection Molding Titanium and Other Reactive Metals,” Weil et al., Journal of Materials Processing Technology, Vol. 176, pages 205-209, 2006; “Manufacturers ‘need better quality titanium PM powders,’” Metal Powder Report, Vol. 60, Issue 10, pages 8-13, October 2005; and “Mass Production of Medical Devices by Metal Injection Molding,” John L. Johnson, Medical Device & Diagnostic Industry, November 2002.